Large Eddy Simulation of a turbulent swirling coaxial jet

This work uses the Large Eddy Simulation (LES) technique to study velocity and passive scalar mixing along with intermittency of a spatially evolving turbulent coaxial swirl jet. The simulations captured the potential core and also predicted high level turbulence intensities in the inner mixing regions. The Probability Density Functions (PDFs) and radial intermittency plots revealed an intermittent mixing behaviour especially in the outer region of the flow where the fluctuations of velocity rapidly change from rotational to irrotational and vice versa. The PDF and radial intermittency profiles exhibit Gaussian and non- Gaussian distributions close to the jet centreline and away from the centreline, respectively.